Product information: Portal 2 Wallscroll "Chell"

Chell is the silent protagonist in the Portal video game series developed by Valve Corporation. She appears in both Portal and Portal 2 as the main player character.

Valve's Erik Wolpaw felt that it did not really matter what kind of person Chell was, noting that playtesters of the first Portal often did not know her name as it was never mentioned. Wolpaw explained that they never mentioned her name as "[players] felt like they had this relationship with GLaDOS, and they wanted GLaDOS to recognize them". Chet Faliszek noted that Chell was the female version of Gordon Freeman's role as a silent protagonist. Wolpaw explained it served the game's humour better if she did not talk, and that if she, the "straight man in a world gone mad," did talk, "it would suck". In fact, there is one part of the first game where GLaDOS seems to get annoyed by Chell's refusal to respond to her, saying, "Are you even listening to me?" (Wolpaw has commented a few times that Chell simply won't give GLaDOS the satisfaction of a response, but he doesn't intend that theory to be taken seriously). In an interview by IGN about Portal 2: Lab Rat, Valve's Michael Avon Oeming commented that, currently, "Chell is more of a storytelling device," comparing her to the Spirit character by Will Eisner, but noted that more may be seen of Chell in the future.

When making Portal 2, developers considered not bringing back the character. However, this was changed as playtesters wanted GLaDOS to recognize them as the person who had killed her in the first game. In her original redesign for Portal 2 developers tried to make her look appealing, yet not overdesigned, with nothing made simply for fashion They explored changing her nationality, and tried to make her look less human due to the "constant dehumanization of these test subjects". Being a test subject, Chell's suit was designed to look neither sexy nor unattractive. The original redesign of the character featured a laboratory hat, which was thought of halfway through the concepting phase. Matt Charlesworth, Valve's concept artist, commented that the hat reminded him of test pilots.

This look was eventually abandoned in favour of returning to her original orange jumpsuit, this time with the jumpsuit wrapped around her waist. Valve's art team explained that this was to give her more freedom and help her stand out more as an individual.